Manufacture of crepe paper



1965 J. D. BOADWAY ETAL 3,220,914

MANUFACTURE OF CREPE PAPER Filed Dec. 27, 1960 2 Sheets-Sheet 1 PAPERJOHN D. BOADWAY RICHARD COLL/NS ATTORNEYS F I G 3 /NVENTORS 1965 J. D.BOADWAY ETAL 3,

MANUFACTURE OF CREPE PAPER Filed Dec. 27, 1960 2 Sheets-Sheet 2 I I I-/5 COMPRESS/ON Lu ORCE I 55 ELASTIC I 55 COMPRESSION I TOTAL I ELCOMPRESSION l 55 l I I I I /.O I -/O. 3 2

u 2 1r 35 9 O Q: LL 1 lg (11 2 I E 5 D: 9 0Q CL 8 I 5 Lu 1 Qc: o E I 1 2Edi a R I'\ i l l I I I I I I I I ELASTIC COMPRESSION W/LL BE LOST I I'2 I I '2 MOI-1 53 I EO/O/v 2 3 5I6 7 FIG /NVENTORS JOHN D. BOADWAYRICHARD COLL/NS ATTORNEYS United States l atent C 3,220,914 MANUFACTUREOF CREPE PAPER John D. Boadway and Richard Collins, GrandMere, Quebec,Canada, assignors to Consolidated Paper Corporation Limited, Montreal,Quebec, Canada Filed Dec. 27, 1960, Ser. No. 78,474 19 Claims. (Cl.161128) This invention relates to the manufacture of crepe paper.

The creping of paper has been practised on a commercial scale for manyyears during which time little change has taken place in the methodsemployed. Essentially, the most commonly-used method involves doctoringor scraping a paper web from a cylinder to which the web adheres in amanner such that the web approaching the doctor blade is compressedwhile in contact with the cylinder and buckles into a folded or wrinkledstructure. Such a method as described, for example, in US. Patent No.790,023 (Arkell) issued May 16, 1905. Following this creping step, thewrinkled or creped web may, if desired, be pressed by passing it betweentwo rolls.

Creping, as described above, may be practised in two ways: dry creping,in which the creping process is applied to a completely dried sheet andwet creping, in which the creping is done on a partially dried sheet oron a thoroughly dewatered, pressed sheet. After the creping operation,the drying of the sheet is completed. A further form of wet creping,commonly known as off machine creping involves the rewetting of acompletely dried uncreped sheet followed by a wet creping. The method ofthe present invention relates primarily to wet creping.

For creping to take place it is neoesasry that the sheet of paper bepressed on and adhere to the creping cylinder or roll. The sheet isdoctored off the cylinder and varying degrees of compression can beimparted to the web depending on the angle between the creping doctorand the roll, the adhesion between the web and the cylinder and otherfactors. The sheet is compressed ahead of the creping doctor and the webslips on the cylinder and is crowded together. The compression force andamount of crowding together is progressively less at greater distancesfrom the doctor due to the effect of friction between the web and theroll. Immediately in front of the doctor the compression force becomesso high that the web buckels away from the cylinder and becomes foldedover repeatedly so that it slides out on the doctor in pleated form.

One difliculty with this regular creping method is that the foldedstructure often tends to pull out in subsequent handling by papermachines and pulls out too readily in the finished product. Thus, whilethe paper is stretchable, the resistance to the stretching force is verysmall. Furthermore, the sheet which is produced generally has relativelydeep pleats which prevent intimate contact between the sheet and thedryers thus making the drying process difiicult and inefficient.

Attempts have been made to reduce both these difiiculties by putting thecreped sheet through a pair of rollers. This irons the large folds inplace thereby increasing the force required to pull them out. However,small folds and any sheet compression are usually lost as the sheet isfairly free to elongate during its residence in the nip.

It is therefore a main object of the present invention to provide ameans by which the degree of crepe can be set over a wide range, andalso a product, relatively smooth in surface structure, having hightensile properties throughout its limits of stretchability.

The method of manufacturing crepe paper according to the presentinvention comprises causing a web of paper to adhere to a first conveyormeans with a first peripheral speed and transferring the web of paper bylongitudinal movement to a second conveyor means moving with aperipheral speed less than first peripheral speed, and causing the webto be freed from adherence to the first conveyor means. The web passesbetween and in contact with both said conveyor means, after which it isfreed from contact with at least the first conveyor means. The web iscompressed immediately after creping while held in the shortened orcreped condition so as to press the crepe in place and to prevent thecrepe from pulling out.

More specifically, the web of paper is passed through a nip formedbetween two rolls rotating in mutually op posite directions and withdifferent peripheral speeds. The web of paper is made to adhere to theroll having the faster peripheral speed before entering the nip, iscreped, pressed between the rolls, and then is freed from adherence tothe faster roll, after passage through the nip. The web may adhere tothe slower moving roll after passage through the nip, but this is notessential; all that is necessary is that the web should not adhere tothe faster moving roll after passing through the nip.

Apparatus according to the invention for carrying out the above processcomprises a first roll, a second roll forming a nip with the first rollthrough which nip a web of paper is adapted to be passed and compressedduring such passage, and a drive mechanism adapted to rotate said rollsin mutually opposite directions at speeds such that the peripheral speedof the second roll is less than that of the first roll.

From the above, it will be seen that the web of paper is pressed whileit is held by pressure of the nip in its shortened or creped condition.The method according to the invention, therefore, eliminates adisadvantage of present creping methods in which the pressing is done atan appreciable time after, and at a distance from, the creping operationsuch that the web has been removed from the roll and much of theoriginal crepe is lost. In addition, the method according to theinvention imparts desirable properties to the finished product. Whereasin existing creping methods the sheet buckles and folds as materialaccumulates in front of the doctor, in the method according to theinvention the sheet need only compress and wrinkle sufiiciently to matchthe speed of the second roll. Hence, by adjusting the differential speedto a proper value, the crepe can be made much finer and more uniform.Different creping may be obtained by varying the differential speed.Also, whereas when a conventionally creped sheet is pressed in aconventional roll nip the small wrinkles are flattened, lengthening theweb, according to the present invention the web is held in compressionas the nip pressure increases to its maximum value. This not onlypresses the small wrinkles in place and bonds them together but causes acertain amount of the elastic deformation which takes place ahead of theroll nip to become a permanent deformation. The imparted crepe is lesslikely to be lost in subsequent operations on the web. In fact, byproper adjustment of such variables as the nip pressure and differentialspeed, etc., it is possible to impart desirable properties, such asstretchability to the finished product without actually visibly crepingthe web. The pressing action also leads to a flat, smoother sheetenabling more efiicient heat transfer when the sheet comes into contactwith the drying cylinders.

The final product will be superior in many ways to conventional crepedpaper. The paper, while highly stretchable, will exhibit less visiblecrepe and the force required for extension will be greater than that forordinary creped paper. In addition, it will be possible to obtain asmoother, better printing surface at least on one side of the sheet,than is possible by present conventional creping methods.

The invention will now be described with reference to the accompanyingdrawings, in which:

FIGURE 1 shows a plan view of apparatus capable of carrying out theprocess according to the invention,

FIGURE 2 shows an elevation view of the apparatus illustrated in FIGURE1, with the driving mechanism for the rolls omitted,

FIGURE 3 is an expanded view, in section, of the paper web passing"between two of the rollers shown in FIG- URES 1 and 2, and

FIGURE 4 is a graph showing compressive force, elastic compression andtotal compression in the paper web as a function of distance as the webpasses through the regions shown in FIGURE 3.

As shown in FIGURES 1 and 2, the web 19 to be treated should be in apartly wet state and is first pressed against a first creping roll 12 byan auxiliary transfer roll 11. The nature of the surfaces of these tworolls should be such that the web 19 will adhere firmly to the firstroll 12 after being pressed on by the transfer roll 11. The first roll12 in operation forces the web adhering to its surface into the nipformed between this first roll 12 and a second creping roll 13. Both ofthese creping rolls 12 and 13 are connected to a driving mechanism,which in this example consists of couplings 15, gear reducers 16,variable gear drive 17 and belt drive 18 (as shown in FIGURE 1), in sucha way that the second roll 13 is run at lower peripheral or surfacespeed than the first creping roll 12. The difference in peripheral speedof the two rolls should not be too great, so that the paper will notcrowd together too much thereby causing irregular creping. The frictionof the web against the second slow-moving roll causes it to becompressed in region 20 just before the nip, while it adheres to thefirst roll 12 at points ahead of the nip between the two rolls. Thiscompression causes the web to slip on the first roll 12 near the nip inresponse to the compression force and causes the web to be shortened andreduced in surface speed in order to match that of the second crepingroll.

The apparatus of FIGURE 1 also includes a lever mechanism 14 whereby thepressures between the rolls can be adjusted. The complex drive mechanismshown in FIGURE 1 can be simplified to include a pair of gears betweenrolls 12 and 13 whereby constant speed differential can be easilymaintained.

FIGURES l and 2 show the axes of the three rolls in one horizontalplane. This is convenient, since the rolls will all deflect by their ownweight giving even pressure. Rolls supported by their ends will deflectunder theirown weight; one might represent this diagrammatically byshowing the long axis of the roll as a line with a sag or curvature. Ifthis roll has to make contact with another roll (or any other object)the contact between the two will also contain this sag. The idealcondition therefore would be for the sag line (or axis curvature) ofeach roll to be the same so that the points of contact (along the wholeline of contact) will be uniform and the pressure even along this line.The simplest way to approach this ideal condition is for the axes ofthese rolls to lie in one and the same horizontal plane. Where the rollsdiffer markedly in weight, size and material, i.e., in their deflectioncharacteristics, other arrangements might be desirable. Here it isassumed that the rolls are roughly similar in this respect. However, itis to be understood that the rolls may be differently arranged. It alsomay be desirable to use a fourth roll after roll 13 to assist in causingthe web to follow roll 13.

The present invention is best adapted to a given situation if theinteraction between the different variables involved is understood. Theadhesion force between a web and a roll is found to have time dependentand time independent components. The adhesion force obeys the equation:

F,,=A+Be- Where F =The adhesion force t seconds after release ofpressure.

A=The adhesion force after infinite time. B=A constant.

k=A constant.

t=The time after release of pressure.

The mathematical form of the time-dependent component is what one wouldexpect if a vacuum were to be created between the web and the surface.The term B could be called the maximum vacuum force and k the porosityfactor. On low speed paper machine operation with a corresponding longtime interval between pressing and creping, the effect of the termBebecomes negligible, but it can increase the adhesion force on highspeed machines.

Adhesion force acts to hold the web to the roll face of the roll 12 inspite of a compression force which is built up. The maximum compressionforce which can be built up before the web buckles away from the roll isas given by the equation:

, 2 a 12mV Where =Centrifugal force in ft. lb./in.

This equation shows the competition which exists between adhesion andcentrifugal forces. The importance of the latter however is very smallexcept for sheets of very high mass on high speed machines. It is seenthat the adhesion force is more effective in giving compression to theweb with larger diameter creping rolls.

The values of the constants A and B in the adhesion force equation arefound to be dependent upon various factors. Higher nip pressures giverise to higher adhesion forces provided the moisture content is correctfor that pressure. The low moisture content webs adhere best with highnip pressures whereas high moisture content Webs adhere better withlower pressures. Sheets with moisture contents below 30% adhere to rollsurfaces with too little adhesion to be very effective, especially whenfine creping is required. This interdependence of nip pressure and webmoisture is important when attempting to design the equipment and locateit with relation to the other components of the papermaking equipment.The above statements with regard to moisture content are applicable onlyto wet creping operations. A dry creping operation according to theinvention will be described farther on.

The adhesion to roll surfaces was also found to be a function of thematerial used. Chilled iron and granite surfaces Were found to have thehighest adhesion forces and to be very satisfactory; rubber, while itpossesses inuch higher frictional characteristics, has a low adhesionorce.

The friction between the web and roll surface performs an importantfunction in the process. The friction force is proportional to the areaof web. For the web to compress on the surface of the first roll it mustslip and hence friction limits the region of sheet compression. Moreimportant, if the compression leads to buckling of the sheet away fromthe roll surface due to the limit of the adhesion force having beenreached, then friction limits the size of area buckling and hence thesize of crepe or wrinkle.

The friction per unit area generally bears a linear relationship toforce between the web and the roll. The equation for such a force is:

F =Frictional force per unit area.

F =Frictional force per unit area with zero pressure. Coefficient offriction.

p=P-ressure between web and roll surface.

The frictional properties of webs on surfaces do not appear to beaffected to any marked extent by the moisture content. The frictionalproperties are, however, influenced by the pressure which is used topress the sheet to the surface and also by the nature of the surface.

The adhesion to surfaces is influenced by the temperature gradientbetween the surface and the web. It has been found that the adhesion toa hot roll in less than the adhesion to a cold roll. This is used toadvantage to control the adhesion forces which are essential to theworking of the present invention. For example, two iron rolls chilled totemperatures below the ambient tem perature could be used for rolls 12and 13 of FIGURE 2. The transfer of the web from roll 12 to roll 13 innip 20 could also be effected by heating roll 12 and cooling roll 13.Also, it has been found that the adhesion to surfaces is influenced bythe wetness of the surface. In this case, the surface tension of theliquid film supplies a bonding force. Thus, the web will transfer from adry surface to a wet surface of the same material. Hence in the exampleabove transfer can be made by keeping roll 13 wet and roll 12 dry.

The understanding of the process according to the invention would beincomplete without a knowledge of the way in which wet webs deform. Ithas been found that wet webs have both elastic and plastic properties.Up to a limit, which could be termed the elastic limit, the web acts asan elastic material and will compress lengthwlse and expand again onrelease of the pressure. Beyond this point the sheet yields and deformsreadily by a considerable amount, this deformation giving rise to awrinkling of the sheet. The behaviour of a web in compression isinfluenced by its moisture content. The web behaviour is influenced bynip pressure perpendicular to the web surface during lengthwisecompression but does not appear to be influenced by pressing prior tobut not during sheet compression. One interesting observatron is thatthe amount of elastic deformation which can take place is less at highthan at low nip pressures. Thus with the process and apparatus asdescribed in the present HIV-611E011 some of the elastic compressivedeformation which takes place ahead of the nip of the rolls laterbecomes pressed in place.

The above information allows an explanation of what happens as a webpasses through the nip of the two rolls running at different peripheralspeeds. FIGURE 3 shows a schematic arrangement of the roll nip. FIGURE 4is a graph showing the compression force and deformations which mighttypically occur using two rolls, each 24" in diameter, running at a 12%differential in speed.

In region 1 of FIGURE 3 the sheet adheres to the roll and isuncompressed. At a certain point, compression of the web begins andthrough region 2 the sheet deforms elastically slipping more and morewith respect to the surface of roll 12 until the yield point is reachedand in region 3 the web deforms and may wrinkle slightly on the sideaway from the roll to which it adheres. In region 4 this top sidebrushes roll 13, and since it will still have a slight relative movementto that roll, the wrinkling on the top will be pushed back. In region 5the sheet will have acquired the surface velocity of roll 13 and will beslipping with respect to roll 12. In this region the sheet is pressedheavily in the nip between the rolls and some of the elastic compressionwhich occurred in region 2 becomes permanent. In region 6 the web iscarried away on the surface of roll 13.

FIGURE 4 presents an example of the deformation which might occur insuch a process.

Although larger rolls should be more effective, rolls at least 2 feet indiameter should preferably be used for carrying out the processaccording to the invention. The first roll should not be less than 8inches in diameter and the second roll should be at least 1 foot indiameter. The two rolls which run at differential speeds must beconnected together with a differential speed mechanism capable oftransmitting high torque. The coefficient of friction of the web betweenthe two rolls is high (in the order of 1) and hence the force betweenthe rolls is of the order of the nip loading used between these rolls.Hence the drive to the first roll must be designed to transmit power tothe roll of:

Where The second roll which is run at low speed must be braked, i.e.,power must be removed from it to act against the nip force. The drivemust be capable of transmitting this braking power:

S2MNW P 33,000

Where:

P =Power to be removed by slower moving roll. S =Surface speed of slowermoving roll in f.p.m.

The differential speed mechanism will feed this power back to the firstroll so that the power consumption of (P P in the process will be:

Consider roll 12 of FIGURE 2. Its rotation relative to roll 13 is suchas to oppose the force applied to the web by roll 13, i.e., it mustforce the sheet into the nip formed by the two rolls 12 and 13, hence,power must be applied to the roll 12 (power, that is, in addition to theusual power which is used to overcome bearing friction, etc.). On theother hand, while the two rolls rotate in opposite directions, theirsurfaces at the nip are moving in the same direction, therefore at thenip the surface of roll 13 moves in the same direction as the forcesapplied by roll 12, and thus power must be taken out of roll 13 by itsown drive mechanism. That is, roll 13 in a sense is acting as a brake.Obviously then, power must be transferred from roll 12 through the webto roll 13. Because the force on one roll must equal the force on theother and since roll 13 is slower than roll 12, there must be a loss ofpower corresponding to the difference in surface speeds. If the rollsare rigid and cannot deform, then it is the web that deforms and thiswork goes into rearranging the fibrous components of the paper web.

The relative speeds of the machinery preceding and following the crepingapparatus must be such that the paper after creping will be moving atslower speed. This slower speed should be slightly higher than thesurface speed of roll 13 since a small part of the compression will bepulled out in pulling the web from the roll 13.

The nip pressures to be employed for the process can be varied to obtainthe required paper properties to compensate for such factor as moisturecontent. The pressure at the nip of the rolls 11 and 12 pressing the webonto the first roll 12 influences the adhesion and friction of the webon the roll surface and hence the fineness of crepe. The pressurebetween the two differential speed rolls influences the pressing in ofthe crepe product and hence the flatness and mechanical properties ofthe finished sheet.

The roll surfaces of rolls 12 and 13 should be such as to give maximumadhesion and friction if the finest crepe with maximum extension force,or resistance to stretching is desired. The surfaces should have a finefinish for best adhesion and friction so as to enable the web to slipover the surface without breaking the adhesive bond. Roll 13 should havea slightly higher adhesion and friction than roll 12 (with relation tothe web) so that the web will transfer from roll 12 to roll 13. This maybe accomplished by a proper selection of roll materials or the nature ofthe roll surfaces or, as mentioned above, by maintaining the rolls at adifferent temperature or moisture level. For example, using polishediron rolls for roll 12 and roll 13, roll 12 may be steam heated from theinside and roll 13 water cooled from the inside.

Referring to FIGURES 1 and 2, the auxiliary transfer roll 11 shouldgenerally be of a soft material such as rubber so that the wet web canbe pressed evenly onto the first roll 12. Alternatively, a simple Wetfelt carrying the web may be used to press the web against the firstroll. The first roll 12 may be either of hard or soft elastic material,whereas, the second roll 13 should be of hard material.

If a hard material is used for roll 12, the surface of the roll cannotdistort and as result shear will occur in the nip. As mentioned theadhesion and friction properties of rolls 12 and 13 should be such thatthe slippage as a result of the shear at the nip centre occurs betweenthe web and roll 12 rather than between the web and roll 13 so that theweb on the outgoing side of the nip will follow roll 13. The shear whichoccurs gives rise to some displacement in the web itself, moving fibreswhich are not well bonded so that better ultimate strength propertiescan be achieved. The strength of a sheet can be related to its bondedarea, i.e., to the area of contact between the individual fibres. If asheet is compacted by moving fibres together, more points of contact arecreated (or the bonded area increased), so that one can assume thatafter a pressing operation, as takes place in the nip (between rolls 12and 13) following this fibre moving, that the moist or dried web willhave better strength properties than would be otherwise possible.

If soft, elastic, rubber material is used for the first roll 12, theaction is quite different. The rubber has a high coefficient of frictionbut low adhesion to the wet web, and can itself stretch. Hence, withdifferential speeds between rolls 12 and 13 the surface of rubber roll12 will be slowed down ahead of the nip in the regions described inFIGURE 3 as regions 2, 3 and 4, so that the surface speed in region willmatch that of roll 13. On the outgoing side of the nip, the rubbersurface will be in the stretched condition because of the braking effectof roll 13. As a result of this, the Web will not slip on the surface'of roll 12 as it approaches the nip, but will compress with it andbecause of low adhesion there will be a tendency for a coarser crepethan would be the case for a hard roll. There will also be no shear atthe nip centre as the surface speed of both rolls will be that of roll13. On the outgoing side of the nip the rubber surface of roll 12 willsuddenly snap back to its normal unstressed position and in so doing itwill tend to free the web and allow it to follow roll 13.

Thus, while the aforementioned creping process is operable using soft,resilient surfaces for the first roll 12,

the use of such surfaces is somewhat limited to the extent that itssurface deformation characteristics are able to compensate for itsrelatively high friction characteristics. In the case of hard,relatively non-deformable surfaces, compression apparently takes placenot through surface deformity but through a combination of shear andsurface slippage of the web on the faster-moving roll 12.

The proper selection of material for the surfaces of rolls 12 and 13 istherefore an important consideration when using the method according totheinvention. The actual choice, however, is dependent somewhat on thepaper properties desired in the final product.

The compression process can be carried out at varying moisture contentthrough appropriate adjustment of nip pressures between the rolls.Difficulty will be encountered however When attempts are made to carryout the process with less than 30% water content in the paper web due tothe tendency for webs of this moisture content to develop differentialstresses which cause them to Wrinkle and cockle so that it is difiicultto make them adhere properly to a surface. On the other hand, if theprocess is carried out when the web is too wet, the compression may pullout in later drying, since the web will be delicate at this highmoisture content and the nip pressure in the process limited to lowvalues. The upper limit of the moisture content is about or less of theweight of the wet web. However, in the interests of economy, it willoften be less expensive to carry out the process at moisture contentsobtainable after the presses on a conventional paper machine, ratherthan at the lower moisture contents obtainable through an interruptionof the drying operation. This creping process can, therefore, be carriedout on a conventional paper machine either before drying or byinterruption of the drying process.

In certain cases, it may even be desirable to perform the methodaccording to the invention in successive or multiple operations,although the amount of creping can be varied considerably using only asingle operation.

In its usual form the process according to the present inventionproduces a product in which the crepe is slightly wrinkle-d. The sheettransfer in the compression nip from roll 12 to roll 13. The wrinklingbecomes more pronounced as the speed difference is increased and theadhesion to roll 13 becomes progressively poorer due to a combination ofthe higher speed differential and the roughness of the sheet surface.Finally at some point which depends on the relative surface adhesion ofrolls 12 and 13 the process becomes unstable and spasmatically the sheetleaves the nip adhering to roll 12 with no compression imparted to it.

However, if the differential in speed between rolls is further increaseda point is reached at which the adhesion to roll 12 ahead of the nipfails and the sheet is folded over in a pleat which is then pressedfirmly in place by the shear and pressure of the nip. The sheet thenleaves the nip freely, adhering to neither roll 12 or 13. While theresultant sheet will have very high stretch properties, the force ofextension will also remain high.

While the above description applies to a newly-formed paper web, it isalso possible to apply it to a previouslyformed and dried web as long asthe dried web is rewetted sufficiently for it to conform to the usualcharacteristics of a wet web.

It is also possible that the method according to the invention could beapplied to the dry creping of paper webs. For example, the conventionaldoctor blade could be replaced by roll 13, which would possessfrictional properties higher than that of the roll over which the paperis passing, usually a Yankee dryer cylinder, and have a surface speedlowerthan that of the dryer cylinder. This would cause the sheet to slipon the dryer cylinder ahead of roll 13 and become pleated, then whileheld in place this pleating would be pressed to the sheet 'on passingthrough the nip. This coarse creping action together with the highfrictional characteristics of roll 13 would allow the sheet to breakfree from the dryer cylinder. Essentially, then the system would besimilar to that shown on FIGURE 2. In the operation of a Yankee machine,for example, the conventional pressure roll pressing the wet sheet onthe Yankee dryer cylinder would represent roll 11, the dryer cylinderwould represent roll 12 and the creping doctor would be replaced by roll13.

What we claim as our invention is:

1. A method of manufacturing crepe paper comprising causing a web ofpaper to adhere to a first conveyor means moving with a first peripheralspeed, transferring the web of paper by longitudinal movement to asecond conveyor means and causing the web to be freed from the firstconveyor means, the second conveyor means moving with a peripheral speedless than the said first peripheral speed, the Web of paper passingbetween and in contact with both said first and second conveyor meansand being compressed in a direction perpendicular to its surface whileit is in contact with both said conveyor means, the surface of saidsecond conveyor means being non-resilient.

2. A method of manufacturing crepe paper comprising passing a moving webof paper adhering to a rotating first roll through a nip formed betweensaidfirst roll and a second roll rotating in a direction opposite to thedirection of rotation of the first roll and having a lower peripheralspeed than the first roll, the web of paper being pressed between therolls as it passes through the nip and being free from adherence to thefirst roll after passage through the nip, the surfaces of said first andsecond rolls being non-resilient.

3. A method as claimed in claim 2 wherein the web of paper adheres tothe second roll after passage through the mp.

4. A method as defined in claim 2, wherein the web of paper is wet.

5. A method as defined in claim 4, wherein the moisture content of theweb is between 30% and 80% of the weight of the wet web.

6. A method as claimed in claim 2, wherein the second roll has a highercoefficient of friction than the first roll.

7. A method as defined in claim 2, wherein the difference in peripheralspeed of the two rolls is less than that required to produce a visiblewrinkle in the web.

8. A method of manufacturing crepe paper comprising causing a moving webof paper having a moisture content between 30% and 80% of the weight ofthe wet web to adhere to a first cylindrical roll having a diameter ofat least 8 inches passing the web through a nip formed between saidfirst roll and a second cylindrical roll having a diameter of at least 1foot, said second roll rotating in a direction opposite to the directionof rotation of the first roll and having a lower peripheral speed thanthe first roll, the web being pressed between the rolls as it passesthrough the nip, and causing the web of paper to be freed from adherenceto the first roll after passage through the nip, the surfaces of saidfirst and second rolls being nonresilient.

9. A method as defined in claim 8, wherein the difference in peripheralspeed of the two rolls is less than that required to produce a visiblewrinkle in the web.

10. A method as claimed in claim 8, wherein the web of paper adheres tothe second roll after passage through the nip.

11. A method as defined in claim 8, wherein the second roll has a highercoefiicient of friction than the first roll.

12. A method as defined in claim 8, wherein the axes of rotation of thetwo rolls are horizontal.

13. A method as defined in claim 8, wherein the axes of rotation of thetwo rolls lie in a horizontal plane.

14. A method as defined in claim 2 wherein adhesion of the moving web ofpaper to the rotating first roll is controlled by controlling thetemperature of the first roll.

15. A method as defined in claim 2 wherein the relative temperatures ofthe first and second rolls are controlled.

16. A method as defined in claim 2 wherein the relative surface wetnessof the first and second rolls is controlled.

17. Apparatus for the manufacture of crepe paper comprising a firstroll, a second roll forming a nip with the first roll through which aweb of paper may be passed and compressed simultaneously in twodirections, one direction being that in which the paper is travellingand the other being that perpendicular to said direction of travel, thesurface of said first roll being non-resilient and characterised in thatsaid web will slip on said first roll when said web is compressed insaid two directions, the surface of said second roll being non-resilientand characterized in that said web will not slip on said second roll butwill adhere preferentially to said second roll when said web iscompressed in said nip and shortened and reduced in surface speed inorder to match the surface speed of said second roll and will pass outfrom said nip not adhering to said first roll, drive means adapted torotate said rolls in mutually opposite directions at speeds such thatthe peripheral speed of said second roll is less than that of the firstroll, and means adapted to control the nip pressure between said firstand second rolls.

18. A method of manufacturing crepe paper comprising causing a movingweb of paper having a moisture content between 30% and of the weight ofthe wet web to adhere to a first cylindrical roll having a diameter ofat least 8 inches passing the web through a nip formed between saidfirst roll and a second cylindrical roll having a diameter of at least 1foot, said second roll rotating in a direction opposite to the directionof rotation of the first roll and having a lower peripheral speed thanthe first roll, the web being pressed between the rolls as it passesthrough the nip, and causing the web of paper to be freed from adherenceto the first roll after passage through the nip, said first rool havinga soft elastic surface and said second roll having a hard surface.

19. Paper produced by the method of claim 1.

References Cited by the Examiner UNITED STATES PATENTS 1,548,790 8/1925Lorenz 162111 2,624,245 1/ 1953 Cluett 154--33.05 2,633,430 3/1953Kellgren et a1 154-3305 2,947,058 8/ 1960 Landells et a1. 15433.05

FOREIGN PATENTS 327,460 10/ 1920 Germany.

ROBERT F. WHITE, Primary Examiner. CARL F. KRAFFT, EARL M. BERGERT,Examiners.

1. A METHOD OF MANUFACTURING CREPE PAPER COMPRISING CAUSING A WEB OFPAPER TO ADHERE TO A FIRST CONVEYOR MEANS MOVING WITH A FIRST PERIPHERALSPEED, TRANSFERRING THE WEB OF PAPER BY LONGITUDINAL MOVEMENT TO ASECOND CONVEYOR MEANS AND CAUSING THE WEB TO BE FREED FROM THE FIRSTCONVEYOR MEANS, THE SECOND CONVEYOR MEANS MOVING WITH A PERIPHERAL SPEEDLESS THAN THE SAID FIRST PERIPHERAL SPEED,
 19. PAPER PRODUCED BY THEMETHOD OF CLAIM 1.